John Walton, 58, Wal-Mart heir

BENTONVILLE, Ark. -- John Walton, the billionaire son of Wal-Mart founder Sam Walton and a member of the company's board, died yesterday in a plane crash in Wyoming.

Mr. Walton, 58, of Jackson, Wyo., was piloting an ultralight that crashed shortly after takeoff from the Jackson Hole Airport in Grand Teton National Park, the company said. He was pronounced dead at the scene, and the cause of the afternoon crash was not known, officials said.

The plane was an experimental ultralight aircraft with a small, gasoline-powered engine and wings wrapped in fabric similar to heavy-duty sail cloth, officials said.

In March, Forbes Magazine listed John Walton at number 11 on its list of the world's richest people, with a net worth of $18.2 billion. He was tied with his brother Jim, one spot behind his bother Rob, and just ahead of his sister, Alice, and his mother, Helen.

Mr. Walton joined the board of Wal-Mart Stores Inc. in 1992 but did not work for the company.

''We're sad that John Walton, who was well-known and much-loved in this valley, died doing something that he loved to do, which was fly aircraft," said Joan Anzelmo, a spokeswoman for Grand Teton National Park.

''I saw parts of it," she said of the plane. ''I didn't realize what I was seeing at first. It was so lightweight, it looked like a giant model airplane."

Anzelmo said officials notified the Federal Aviation Administration and National Transportation Safety Board.

''Because this is a homemade, nonregistered, experimental aircraft, at least today they told us there was not going to be an investigation," she said. Grand Teton rangers will conduct their own probe, as is done with any major accident in the park, she said.

Wal-Mart spokeswoman Mona Williams said the company notified its employees worldwide of Mr. Walton's death.

Walton was an Army veteran who served as a medic with the Green Berets during the Vietnam War. He was awarded the Silver Star for saving the lives of several members of his unit while under enemy fire, according to the company.

The company said Mr. Walton pursued a variety of business interests, including working as a crop duster in the 1970s and building boats in the 1980s. More recently, he had formed a holding company, True North, to oversee various business interests.

Mr. Walton leaves his wife, Christy; his son, Luke; his mother, Helen; two brothers, Rob and Jim; and a sister, Alice.

Funeral arrangements were not immediately announced.